Ratchet operating mechanism for drills.



F. A. MMERSON.

nATcHr-:T OPERATING mEcHAms-M .EUR Dams.

APPLICATIGN FILED IUNE I9, 195.

mmm Feb .5,1918.

mm mx. @Q

F. A. HMERSGN.

RATCHET OPERATING MECHANISM FOR DBlLLS.

APPLCAlON FILED1UNE!9,I915. l.

@tamed Feb.' 5, 1918.

3 SHEETS--SHEET 2.

I:r I3. IIIVIEHSON. HATCHET OPERATING MECHANISNI FOR DRILLS.

' Patented Feb. 5,1918.

APPLICATION FILED JUNE I9, i915.

' s sHEHsJ-SHEEI a.

359; @Hom/w .'iii-NrrnnI sTArns" N API-ENT oErrcE,

- FRANCIS A; JIMERsoN, or ATHENs, PENNSYLVANIA, AssICfNoR To INGERso'LLRANn COMPANY, or' JERSEY CITY, NEW-JERSEY, A CORPORATION OE NEW JERSEY.

RATCHET OPERATING MEOHANISM FOR nRILLs.

To all fw'wmz't may concern: v

Beit known that I, FRANCIS A. .Inunnsom a citizen of the. United States, residingat Athens, in the county of Bradford and State of Pennsylvania, have invented a certain new and useful Improvement in RatchetOperating Mechanism for Drills, of which the following is a specification e This invention relates to fluid operated rota ry drills, and more particularly to drills of this type known as close corner drills, which are `designed tofoperate in restricted spaces, and particularly relates to improvements in the type of drill shown in theV patent of Caid H. Peck, No. 1,172,901granted February 22d, 1916.

. These drills, as usually constructed, consistof'an elongated casing in the extremityY of one end of which islocated a rotary spindle which is generally operatedv by a series of ratchet levers driven through the medium of small Vreciprocating motorfelements set in the other end of the casing.

Oneobject of the present inventionisto provide a ratchet mechanism which will allow the ratchet teeth `on the spindleto be of considerable size, Vand consequent strength, and yet, at the same time,fperniit a rapid movement ofthemotor pistons 1n comparison to the movement of the spindle, thus enabling the motor elements to be of Vsmall size and yet produce a powerfulfand continuoustorqueon the spindle.' rTIIis re-v sult is accomplished by havingv the' pawl of each ratchet lever of the seriesv successively engagethe same tooth of the spindle, in vcon-Y tradistinction to the usual construction in which the pawl of each ratchet lever engages a new tooth of the spindle.'

A further object of the invention is: to provide a construction havingthe motorpistons engaging and actuating the ratchet' levers without the interposition of. intermediate elements 1n whichmeansare provided to definltely control the "respective positions oflthe ratchet levers withregardV to each other andat the same time, .limitV and control their angular movementfwith respect to the `drill spindle.V

A still further.y object is to provide anarrangement for the ratchetilevcrs and their i Y Speciicationrof Letters Patent.

driving'gmotors wherebyfa plurality ofmo- ,e @we Patented Femeninas. L l Appncationineasrunef1e, 1915. l sefiaiNo. 35,109.

devisedya practical embodiment of which isv l shownV in' the accompanying drawings, in which, l ',l/ ,1 Figure 1 is a side view, partly i section, on the line lf-l of awayv to show the ratchet levers and mechanismA inside elevation. /V Y Fig.v 2 is'. a longitudinal vhorizontal section `on theyline2-2 ofFigJl, andl Fig. 3 isa diagrammatic `view Yshowing the ratchet'mechanism and the positions of the pawls in the various ratchet levers.

The drill, as shown, comprises an elongated casing l, at one extremity ofV which is Jafcylindrical spindle sleeve 2, the ends of which project above and below V4the casing l. In this spindle sleeve 2 is rotatably supported the spindle 3, this spindle having,

anV upperbearing portion Il, acentral toothed `portion 5 anda lower bearing portion 6,

these being all of the same outer diameter. q The bearing portion 6V is journaled in a bushing in the lowerpart of the sleeve 2,

while the bearing portion t is journaled in a bushing 7 which has anupper lia'nge` 8 resting ona'shoulder in the sleevel2. The spindle V3 is provided at`-itsupper end withV a` flange 9 which rests on the upper face of the bushing 8, thus preventing movement of the spindleV in a downwardV direction, while) movement ofthe spindle in an upward direction is prevented by a cap 10 threaded Vinto the upper end of the 'sleevel 2, a ball 'set 11 being` inserted between the ange `9V and the cap 10. 1 Inthe cap'lO `is secured a telescopio feed screw mechanism-12, the details of which formnov part ofthe present invention.. Extending longitudinally ofthe casing are Vthree"ratchet,levers 1S, 14, and,v 15.`

The spindle' ends 16, 17 and 18 of these levers form circular sleeves or straps which e surround" the toothed portion `5 `of the spindle, the spindle forming a bearing or the, other end of the casing are threecylfulcrurn'for the oscillation ofthe levers.V Atl 10i) 60 Fig. 2, and partly broken motor i right angles'to'the lengthof the casing and at right angles to the Alongitudinal axis of the spindle. Reciprocating in the cylinders are pistons 22, 23 and 24, each of which con-V sists of .a piston element 25 anda connecting element Y,2 6'Vwhich is in the form of a ,p'm rigidly secured in the inner side of the piston element and having a longitudinal slot 27 in its Vouter end into which projects aknob 28 ontheend of the lever which is. Y

actuated by'this particular piston, this knob Vbeing free tov slide in the slot 27 to allow @f for the longitudinalmovement dueto the oscillation Vof the levers.V

c VThe three `cyl inders`19, and-21 are not set on the samek line Vwith respect tothe spindle but the inr nercylinder 20 is set nearer the spindle and somewhat between the other two, so that the thandf the cylinders were all on the samev cylinders overlap to a certain extenton the line ofthe spindle axis, enabling the end ofthe casing to be of considerably less height *l line. -fThis arrangement T Of the cylinders also has the advantage that thev spindle ends 0f thelevers canbe close together andiyet the cylinder ends of the upper andY lower levers f need not beat Vany'considerable vangle from kthe'spindle axis. Since by this arrangement f ofthe cylinders'the central lever 14 must be Yao of lesslength' than the upper andA lower l levers 13 and 15, and consequently th'e'piston 23'must1have a shorter Vrecip'rocation in order l Y to-'oscillate the lever 14 through thesame angular distance as thelevers V4 '13 and 15, the cylinder 20 and thepiston28jl are of larger 'Y area than the cylinders19 and 21 and pis-g tons 22 and 24, So` that the piston 23 shall i and 15v a crank 29 isfprovidedbetrween Ythe exertjthe sameV force on the lever 14 as the piston`s22 and 24. Tolimit andcequalize therfangu'lary movement ofthe levers 13, 14

',cylinders and the spindle. The'casing 1 is i split Vdiagonally, on the` axis of thisy crank l 29,'semi-cylindrica1 Vbearing seats 30 being Y Y t c jfor the ends of the crank29 1n which are placedball bearing sets 31 surroundingthe.k

thus-provided in each section of the casing y endsof the crank. VThe crank 29 has'three L offset portions82, 33 and 34, one for each ratchet lever, set at angles of 120 from each the' spindle-In Vtheflleversl, laland 15 "contiguoustoY thespindle V8 are sety respec-f Ativelyppavvls 37,l 38 and 39.V 'These pawls 37, v3ft-and 89 arexnot setV intheir respective levers in the samek position withrespect to the"v longitudinal axes Yof, their levers but are .so 'set that` each A one Vof the series dfrom topk to bottom will successively engage the same tooth of the spindle.` This is accomplished by having the pawl in each lever from the topl to the bottom successively advanced over the preceding pawlwith respect to the longitudinal axes of the levers an angular amount equalto the angular space occupied by one spindle tooth divided by the number of' levers; Taking the specific drill here illustrated as an example and referring Ato Fig. 3 it will be seen that the spindle is provided with ifteen teeth, each one, therefore, occupying an angular space of 24. The pawl in the center lever must, therefore, be placed one-third of 24, or 8, in advance ofthe pawl in the upper lever, with respect to the longitudinal axis of the levier,

while the pawl in the lower lever must be .is immaterial, their relativeY positions being the determining feature. It will be evident, therefore, from the above description that as the crank shaft moves in the direction indicated in Fig. 8 the top pawl will engage toothrof thespindle, move it through a slight angular distance, the pawl in the second lever will then engage the same tooth and move it through the same distance, and the third pawl will complete the cycle, moving theV spindle far enough so that the first pawl can engage a new tooth. Theoretically speaking, to produce this cycle eachpawl should engage its tooth at a point P which is determined by the number of levers, this point being a number of degrees past the upper limit of the cranks movement equal to minus half of the angular space between the cranks, V this distance in the present case amounting to 90 minus 60, or 30,

land the. amount ofangularl movement of this lever aroundits fulcrum from the point 'Pl to the point Pt, where the next lever comes into operation, should be theoretically equaltothe angle through which the lever and `its pawl must move the spindle, that is, the angular space occupied by a single spindletooth divided by thev number of Alevers or vin this particular instance 8, the'same angular amount as the pawls are successivelyadvanced with respect to the longitudinal axes of their levers. In practice, however, in'order that the first pawl ymay surely engage new tooth the throw of the crank 29 must be so calculated with respect tothedlstances of the pawl and the esame maar tenteraem the ranma a 'point that the', angular distance passed thro ughV `by the lever in Vmoving from `P` to P1 isA slightly The reciprocati'oiroff the pistonsis accomplished by air admitted through an inlet passage and controlled by a rotary valve 41 which is operated through a pinion 42 on the upper end of the crank 29.

The operation of the drill Will be evident from the above description. The cylinders 19 and 20 and 21 are successively supplied with air and exhausted by the 'valve 41. When the lever 13 reaches the pointrP in Fig. 3, or slightly thereafter, the paWlA 37 will engage a tooth of the ratchet'and exert a continuous turning movementV on the spindle until the lever reaches theV point P1. During this movement the spindle Will have been moved through slightly more than 8. lVhen lever 13 has reached the point P1, lever/14 will have moved around to the point l), and by reason of the advance of the pawl 38 in this lever over pavvl 37 in lever 13,

pavvl 38 Will engagethe same tooth theoreti- V cally at the point P, but practically slightly later, on accountof the slightly more than 8O movement of the lever 13. Similarly,

when the lever V14 reaches the point P1, lever 15 Will havel reached the point` P and the Ypavvl 39 Will engage the same tooth. as the pawls in the lirst two-levers, also slightly after the lever has passed the Vpoint P.

Whenthe lever 15 has moved around to theV point P1 thelever 13 Will have again moved around to P andrits pavvl will be in a position toengage the next tooth of the spindle.

lt will be seen, therefore, that'there-is a practically constant torque on the4 spindle which results in a very powerful movement of the spindle which is comparatively slow with respect tothe movement of the pistons. It Will be evident that if the three pawls did not engage the same tooth successively, there f wouldv have to be three times as many teeth to get the same slow speed andliigh power,

and the teeth Would be consequently so small that they would be unable to properly transmit the amount of power necessary Without Y prohibitive Wear and breakage. The provisionV of the crank connecting the variousA levers allows the regulation and control of the' respective positions of the levers and limits and equalizes their-*angular movement,

las Well as 'furnishing positive vmechanical control of the valve 4 y v It is to be understood that While the present showing and'description disclose only one specified' modification ofA `this .present invention, other forms yand modilicationsware included within thespirit and scope thereof, asexpressed in the appended claims.

` "'What I claimfis: v

1. In aclose corner drill, a ratchetmechanism comprising a spindle having teeth thereon, a series of paWl carrying levers,

directly connected meansY to oscillateV said levers around said spindle successively thro-ugh. the sameV angle of rotation" and 'paWls' set in said levers engaging said teeth,

the pa'wl in eachsuccessive lever of the series being advanced With respect to the longitui of rotation and pavvls set in said levers en-` gaging said teeth, the paWl in each successive lever of the series bemg advanced with respect to the longitudinal axis of its lever an angular amount in the direction of the spindle rotation equal to the angularspace occupied by a single spindle tooth divided by the number of levers, said means for oscillating the levers through the same angle comprising a crank regulating the respective positions of said levers.

3. In a close corner drill, a ratchet mechanism comprising a spindle having Vteeth thereon, a series of three paWl carrying levers for driving said spindle, said levers arranged vto oscillate .around said spindle successively through the same angle, and pavvls set in said levers engaging saidteeth, the paWl in each successive lever of the series being advanced with respect to the longitudinal axis of its lever in the direction of the spindle rotation an angular amount equal to one-third of the angular space occupied by a single spindle tooth.

y 4. Ina close corner drill, a ratchet mechai nism comprising a spindle having teeth thereon, a series of three paWl carrying dinal axis of its lever in the direction ot the spindle rotation an angular amount equal to f .one-third of the angular space occupied by a single spindle tooth, and means for oscillating the levers through equal angles of'rotation comprisingl a crank mechanism regulating the respectiveV positions of `said levers and limitmg thelr angular movement to an 'j Copies of this patentniay be'ohtained for harhount slightly greater than one-third the i angularspace yoccupied by a single tooth of said spindle. f

547111 al close corner drill, a ratchet mechajrrlsrn'V comprising a spindle having teeth V.fthereonra series'of pawl carrying Vlevers directly connected thereto, means to oscillate said levers laroun'cl v saiol spindle` successively through the same angle of rotation and m hand.

y FRANCIS A. JIMERSON.

ive vcents eachl by addressing the Commissioner ot Patents, Y Washington, D. C. 

